FLUORESCENCE-BASED ASSAY FOR THE DETECTION OF SPECIFIC NUCLEIC ACIDS USING PHOTON COUNTING

摘要

The present assay is directed to a sensitive assay for detecting the presence of small amounts of a specific nThe present assay is directed to a sensitive assay for detecting the presence of small amounts of a specific nucleic acid sequence or sequences in a mixture of sample nucleic acids using photon counting, wherein the sample nucleic acids have not been amplified by polymerase chain reaction prior to assay or further separated from the mixture of sample nucleic acids once the mixture has been isolated from its original source. In one aspect, the present assay comprises binding a mixture of sample nucleic acids to a solid matrix; contacting the matrix-bound sample nucleic acids with a fluorescent-labeled nucleic acid probe; washing the matrix-bound sample nucleic acids under stringent conditions to remove any free or non-specifically bound fluorescent-labeled nucleic acid probe; removing the specifically bound fluorescent-labeled nucleic acid probe; and detecting the presence of the specifically bound fluorescent-labeled nucleic acid probe using photon counting, wherein the presence of fluorescent-labeled probe is indicative of the presence of a target nucleic acid or nucleic acids in the biological sample. In another aspect, the assay includes a polypeptide-tagged nucleic acid probe and a fluorescent-labeled antibody that is specific for the polypeptide tag of the nucleic acid probe, wherein the fluorescent-labeled antibody is detected using photon counting and indicative of the presence of a target nucleic acid or nucleic acids in the biological sample.